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WOS: 000389165400048 The present study describes the synthesis, spectroscopic and electrochemical characterization of Cu(II)sulfathiazole (Hstz:4-amino-N-(1,3-thiazol-2-yl) benzene sulfonamide) complexes with dien (diethylenetriamine). The techniques used for the characterization have been single crystal X-ray diffraction, IR and EPR. The structural study indicated that the [Cu(stz)(2)dien] complex crystallizes in the monoclinic space group Pna2(1) with Z= 4. Two sulfathiazole anions were coordinated to the metal ion through N atom of the deprotonated sulfonamido group. Almost square-bipyramidal geometry with value of tau parameter approximate to 0.048 has been completed with three nitrogen atoms of dien molecule. The most important spectral features of the complex with its structural,properties were compared and discussed. The electrochemical study indicated the formation and the irreversibility of the mixed ligand metal complex. Biological study of the [Cu(stz)(2)dien]center dot 3H(2)O against Gram-positive and Gram-negative bacterial and fungal strains complex showed very strong antibacterial activity with MIC values ranging from 1 to 4 mu g/mL. (C) 2016 Elsevier Ltd. All rights reserved. Ondokuz Mayis University Research FundOndokuz Mayis University [PYO.FEN.1904.12.019] We would like thank to Ondokuz Mayis University Research Fund (PYO.FEN.1904.12.019) for financial support.

WOS: 000377246800004 Simple, rapid, sensitive and low cost voltammetric method for simultaneous determination of acetazolamide and theophylline in pharmaceutical formulations, was developed using a static mercury drop electrode (SMDE). Well-defined voltammetric peaks were obtained at-0.87 and-1.33 V for acetazolamide and-0.21 V (vs. Ag/AgCl) for theophylline in Britton-Robinson (B-R) buffer (pH 2.4). The reduction peak currents are found to be linearly dependent on the concentration for the both drugs. Calibration graphs were obtained over the concentration range 1.98 x 10(-6) to 5.94 x 10(-5) M and 2.0 x 10(-5) to 5.6 x 10(-4) M for acetazolamide and theophylline, respectively. The limits of detection (LOD) and quantitation (LOQ) of the procedure were also presented. Factors such as, pH of supporting electrolyte, equilibrium time, frequency, scan rate and pulse height were optimized. The validated voltammetric method was successfully applied for simultaneous determinations of the two drugs. The procedure does not require any sample pretreatment or timeconsuming separation steps.

WOS: 000348955300106 PubMed: 25459691 A novel copper (II) complex of sulfamethazine (4-amino-N-[4,6-dimethyl-2-pyrimidinyl] benzene sulfonamide, Hsmz) ([Cu(smz)(2)bipy]center dot 0.8H(2)O; bipy: 2,2'-bipyridine) has been synthesized and characterized by single crystal X-ray diffraction, EPR, IR, UV-vis and electrochemical methods. The single crystal X-ray analysis indicated that the compound crystallizes in the monoclinic space group P21/c with Z = 4. The central copper (II) ion is coordinated by two bidentate sulfamethazine anions through the nitrogen atoms together with one bidentate 2,2'-bipyridine ligand forming the octahedral geometry. The characteristic vibration bands support the X-ray analysis results. The EPR spectral analysis has led to that the ground state wave function of the unpaired electron of copper ion is d(x2-y2) (B-2(1g) state) and also indicated that the metal ions are located in distorted octahedral sites (D-4h) elongated along the z-axis. The electrochemical studies of the complex were also carried out to determine the active sites of the ligands. The cyclic and square wave voltammetric techniques have been used to determine the complex. (C) 2014 Elsevier B.V. All rights reserved. Ondokuz Mayis University Research FundOndokuz Mayis University [PYO.FEN.1904.09.025] We would like thank to Ondokuz Mayis University Research Fund (PYO.FEN.1904.09.025) for financial support and also Prof. Dr. Orhan Buyukgungor for collecting X-ray diffraction data.

In the title 1:1 co-crystal, C9H10N4O2S2·C6H9N3O2[systematic name: 4-amino-N-(5-methyl-1,3,4-thiadiazol-2-yl)benzenesulfonamide–2-amino-4,6-dimethoxypyrimidine (1/1)], the sulfamethazole molecule is found in the form of the imidine tautomer. In the crystal, the components are linked by a pair of N—H...N hydrogen bonds, which generate anR22(8) loop. Further N—H...N and N—H...O hydrogen bonds link the dimers into [100] chains.

WOS: 000275751900012 A novel histamine-saccharine complex, [Cd( His) 2( Sac) 2], is investigated by X-ray diffraction, infrared (IR) and electron paramagnetic resonance (EPR) spectroscopies. In the complex, histamine has N-tau-H tautomeric form. The crystal packing is stabilized by N-H center dot center dot center dot O hydrogen bonds forming R(2)(2)d(16) and R(4)(2)d(4) ring patterns. In EPR study, the angular variation of the spectra of Cu2+ doped Cd(His) 2(Sac)(2) single crystal shows that two different Cu2+ complexes are located in different chemical environments. Each environment contains one magnetically distinct Cu2+ site occupying substitutional position in the lattice. The vibrational investigation has been carried out on the basis of some characteristic IR bands of histamine and saccharine molecules. (C) 2010 Elsevier B.V. All rights reserved.

WOS: 000257336300010 The diaqua(ethylisonicotinate)(pyridine-2,6-dicarboxylato)nickel(II) monohydrate complex was synthesized and characterized by spectroscopic (IR, UV/vis), X-ray diffraction and electrochemical methods. The Ni(II) ion is bonded to dipicolinate (dpc) through pyridine N atom and one O atom of each carboxylate group, two aqua ligands and N pyridine atom of ethylisonicotinate (ein), form the distorted octahedral geometry. The molecules are connected via O-H O hydrogen bonds, forming R-4(4)(12) motifs in three dimensional networks. IR and UV-Vis spectroscopies agree with the observed crystal structure. The voltammetric behaviour of the complex was investigated in aqueous solution by square-wave and cyclic voltammetry using a NH3/NH4Cl buffer. The square-wave voltammogram of the complex yields three reduction peaks at -0.88, -1.20 and -1.28 V. The irreversible reduction as a shoulder at -1.20 V is due to Ni-dpc-ein complex. The peak at -0.88 V corresponds to irreversible electrode process of Ni(II)-ein complex while the peak at -1.28 V is attributed to the reduction of the coordinated dpc ligands.

28th European Congress on Molecular Spectroscopy -- SEP 03-08, 2006 -- Istanbul Univ, Beyazit Campus, Istanbul, TURKEY WOS: 000246329200038 Crystal structure of [Cu(hsm)(2)(sac)(2)] (hsm is histamine and sac is saccharinate) complex has been determined by X-ray diffraction analyses and its magnetic environment has been identified by electron paramagnetic resonance (EPR) technique. The title complex crystallizes in the monoclinic system, space group P 21/c with a = 7.4282(4), b = 22.5034(16), c = 8.3300(5) angstrom, beta = 106.227(4)degrees, V = 1336.98(14) angstrom(3), and Z = 2. The structure consist of discrete [Cu(hsm)(2)(sac)(2)] molecules in which the copper ion is centrosymmetrically coordinated by two histamine ligands forming an equatorial plane [Cu-N-hsm = 2.024(2) and Cu-N-hsm 2.0338(18) angstrom). Two N atoms from the saccharinate ligands coordinate on the elongated axial positions with Cu-N-sac being 2.609(5) angstrom. The complex is also characterized by spectroscopic (IR, UV/Vis) and thermal (TG, and TDA) methods. The cyclic voltammogram of the title complex investigated in DMSO (dimethylsulfoxide) solution exhibits only metal centred electroactivity in the potential range -1.25-1.5 V versus Ag/AgCl reference electrode. The molecular orbital bond coefficients of Cu(II) ion in d(9) state is also calculated by using EPR and optical absorption parameters. (c) 2006 Elsevier B.V. All rights reserved. Istanbul Univ, Sci Fac

The interaction of acetylsalicylic acid (aspirin, aspH) and nicotinamide (NA) with Co(II) and Ni(II) ions was investigated using square-wave and cyclic voltammetry techniques. In the presence of Ni(II)/Co(II),nicotinamide gave new peaks at -0.85V and soh.12 V, corresponding to the reduction of Ni(II)-nicotinamide(log β1:2 =5.97) and Co(II)-nicotinamide (log β1:2 =5.19) complexes, respectively. In the presence of Ni(II)/Co(II), acetylsalicylic acid gave new peaks at -0.91V and -1.19 V, respectively, corresponding to the reductionof Ni(II)-salicylate (log β1:2 =8.48) and Co(II)-salicylate (log β1:2 =8.14) complexes. In the presence of nicotinamide, Ni(II)-salicylate and Co(II)-salicylate form mixed ligand complexes, reducing at -0.78V (log β1:2:2 =9.68) and -1.14V (log β1:2:2 =8.64), respectively.

[M(saccharinato)2(H2O)4] (M = Cu2+, Ni2+, Co2+) react with nicotinamide to form mixed ligand complexes, [Cu(saccharinato)2(nicotinamide)(H2O)]⋅(H2O) (1) and [M(nicotinamide)2(H2O)4]⋅(saccharinate)2 (2: M = Ni2+; 3: M = Co2+), and their crystal structures have been determined by X-ray diffraction. In 1, the Cu2+ atom in an octahedral configuration is coordinated by two monodentate saccharinato ligands in the trans arrangement through the deprotonated ring nitrogens, by two bidentate nicotinamide ligands, one through the pyridyl ring nitrogen and the other through the amide oxygen, and by a water molecule, thus forming a nicotinamide-bridged one-dimensional extended structure. In the isomorphous complexes 2 and 3, the octahedral metal atom, which rides on a crystallographic center of symmetry, is coordinated by two monodentate nicotinamide ligands through the ring nitrogens and four water molecules to form a discrete [M(nicotinamide)2(H2O)4]2 + structural unit, which captures up and down two saccharinate ions, each through three hydrogen bonds: two hydrogen bonds between two water ligands and the ring N and the carbonyl O atoms and one between the amide N of the nicotinamide ligand and the carbonyl O.

WOS: 000350939200015 PubMed: 25590828 The detailed investigation of an organic nonlinear optical (NLO) squarate salt of 3-phenylpyridinium hydrogen squarate (1), C11H10N+center dot C4HO4-, was reported in this study. The XRD data indicates that the crystal structure of the title compound is in the triclinic P-1 space group. In the asymmetric unit, the 3-phenylpyridine molecule is protonated by one hydrogen atom donation of squaric acid molecule, forming the salt (1). The X-ray analysis shows that the crystal packing has hydrogen bonding ring pattern of D-2(2)(10) (alpha-dimer) through N--H center dot center dot center dot O interactions. The structural and vibrational properties of the compound were also studied by computational methods of ab initio at DFT/B3LYP/6-31++G(d,p) (2) and HF/6-31++G(d,p) (3) levels of theory. The calculation results on the basis of two models for both the optimized molecular structure and vibrational properties for the 1 are presented and compared with the experimental results. Non-linear optical properties (NLO) of the title compound together with the molecular electrostatic potential (MEP), electronic absorption spectrum, frontier molecular orbitals (FMOs) and conformational flexibility were also studied at the 2 level and the results were reported. In order to evaluate the suitability for NLO applications thermal analysis (TG, DTA and DTG) data of 1 were also obtained. (C) 2014 Elsevier B.V. All rights reserved. Ondokuz Maps University Research FundOndokuz Mayis University [PYO.FEN.1904.12.020] We would like thank to Ondokuz Maps University Research Fund (PYO.FEN.1904.12.020) for financial support. Special thanks also go to Dr. Necmi Dege for collecting XRD data and to Dr. Yildiray Topcu for supplying UV-Vis and thermal analysis data.

WOS: 000348955300017 PubMed: 25485867 In this study, [Ni(dien)(2)]center dot smz(2)center dot(Hsmz: sulfamethazine and dien: diethylenetriamine) complex has been synthesized and its crystal structure has been determined by X-ray diffraction technique. The title complex crystallizes in orthorhombic system with space group Pbnb [a=8.556(5), b=16.228(5), c = 28.209(5) angstrom, V = 3917(3) angstrom(3) and Z= 4 . The nickel(II) ion has distorted octahedral coordination geometry. The metal atom, which rides on a crystallographic center of symmetry, is coordinated by six nitrogen atoms of two dien ligands to form a discrete [Ni(dien)(2)](2+) unit, which captures two sulfamethazine ions, each through intermolecular hydrogen bonds. The powder EPR spectrum of Cu2+ doped Ni(II) complex was recorded at room temperature. The vibrational investigation has been carried out by considering the characteristic bands related to the functional groups of the complex. The electrochemical behavior of Ni(II) ions in the presence and in the absence of smz and dien were studied by square wave and cyclic voltammetry. A well-defined irreversible peak at -1.112V different from those of the Ni(II)-smz (-0.876 V) and the Ni(II)-dien complex (-1.064 V) was observed in the solution containing Ni(II) ions, which was attributed to the formation of the new mixed ligand complex of Ni(II) with smz and dien. (C) 2014 Elsevier B.V. All rights reserved. Ondokuz Mayis University Research FundOndokuz Mayis University [PYO.FEN.1904.09.025] We would like thank to Ondokuz Mayis University Research Fund (PYO.FEN.1904.09.025) for financial support and also Prof.Dr.Orhan Buyukgungor for collecting XRD data.

To investigate the effects of noise on mismatch negativity (MMN) responses and the possible benefits of an adaptive directional BEAM microphone in noise during MMN recordings, and to compare the cochlear implant-evoked potential results with normal hearing subjects. Materials and methods: /da/ and /di/ speech stimuli were used to elicit MMN responses in 11 Freedom cochlear implant users and in 11 normal hearing subjects. Speech noise was delivered at 80 dB sound pressure level (-10 dB signal-to-noise ratio). All subjects were tested in quiet and noisy conditions. To compare the microphone effects, MMN responses for the cochlear implant group were recorded with an omnidirectional and adaptive directional BEAM microphone mode in noise. Results: The MMN responses of the cochlear implantees and the normal hearing group were remarkably similar in terms of latency, amplitude, and morphology in both quiet and noisy conditions. MMN peak latencies were significantly prolonged in the noisy conditions compared to the quiet conditions for both groups. There was a significant decrease in MMN latencies when using an adaptive directional microphone in noise. Conclusion: MMN could be a useful tool to evaluate postoperative cortical auditory performance. BEAM technology provides an ease of discrimination similar to quiet settings for cochlear implant recipients in noisy environments (BEAM and Freedom are trademarks of Cochlear Limited).

Naumov, Pance/0000-0003-2416-6569 WOS: 000167079800001 Four novel mixed ligand complexes of Cu(II), Co(II), Ni(II) and Zn(ll) with saccharin and nicotinamide were synthesised and characterised on the basis of elemental analysis, FT-IR spectroscopic study, W-Vis spectrometric and magnetic susceptibility data. The structure of the Cu (II) complex is completely different from those of the Co(II), Ni(ZI) and Zn(II) complexes. From the frequencies of the saccharinato CO and SO2 modes, it has been proven that the saccharinato ligands in the structure of the Cu complex are coordinated to the metal ion ([Cu(NA)(2)(Sac)(2)(H2O)], where NA - nicotinamide, Sac - saccharinato ligand or ion), whilst in the Co(II), Ni(II) and Zn(II) complexes are uncoordinated and exist as ions ([M(NA)(2)(H2O)(4)](Sac)(2)). (C) 2001 Elsevier Science B.V. All rights reserved.

Polymeric copper(II) complex, [Cu(Hacm)2(na)2(H2O)2] [H2acm; acetazolamide, na; nicotinamide] was synthesized and characterized by spectroscopic (IR; infrared spectroscopy, EPR; electron paramagnetic resonance), structural (XRD) and voltammetric structural (CV) methods. The copper(II) compound crystallizes in the triclinic space group P 1 ¯ , Z = 1, with the unit-cell dimensions: a = 7.672 (5) A, b = 8.681 (5) A, c = 11.938 (5) A, α = 90.807 (7)°, β = 98.616 (5)° and γ = 110.647 (5)°. The Cu(II) ion has a distorted octahedral coordination geometry. The crystal packing of the complex is stabilized by intermolecular O–H…O and N–H…O hydrogen bonds. The powder EPR spectrum of copper(II) complex have indicate that the paramagnetic center is in a tetragonal symmetry with the Cu2+ ion having a distorted octahedral geometry. The vibrational investigation has been carried out on the basis of some characteristic IR bands of acetazolamide and nicotinamide molecules.

WOS: 000278122000007 Cyclic voltammetry (CV) and square-wave voltammetry (SWV) techniques have been used to study the binary complexes of Co(II), Ni(II) and Cu(II) with sulfamethazine (SMZ) at a static mercury drop electrode (SMDE) in 0.04 M Britton-Robinson (B-R) buffer. SMZ gave three peaks at 0.01, -1.32 and -1.55 V. Cu(II)-SMZ complex was recognized by a cathodic peak at -0.38 V. Ni(II)-SMZ complex was reduced at more positive potential (-0.77 V) than that of the hydrated Ni(II) ions (-1.08 V). Co(II)-SMZ complex is investigated at pH 7 and 8. The Co(II) complex at pH 7 is appeared as a shoulder at -1.19 V, whereas this peak becomes a well-separated form at pH 8. The study indicated that the SMZ serves as a catalyst in the reduction of Co(II) and Ni(II) ions. From electronic spectra data of the complexes, their stoichiometries of 1 : 2 (metal-ligand) in aqueous medium are determined. The stability constants of the complexes are in agreement with the Irwing-Williams series (Co < Ni < Cu). Science and Research Council of Turkey (TUBITAK-BIDEB)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) The authors gratefully acknowledges the support of this work by The Science and Research Council of Turkey (TUBITAK-BIDEB). They are also grateful to Dr. Ahmet Bulut (Ondokuz Mayis University, Samsun) and Dr. Ahmet Karadag (Gaziosmanpasa University, Tokat) for their valuable contributions.

Polymeric copper(II), [Cu(μ-dpc)(μ-4-hymp)] n (1), and monomeric nickel(II), [Ni(dpc)(4-hymp)(H2O)2]·H2O (2), (dpc: dipicolinate, 4-hymp: 4-hydroxymethyl pyridine), dipicolinate complexes have been prepared and characterized by spectroscopic (IR, UV–Vis, EPR), thermal (TG/DTA), X-ray diffraction technique and electrochemical methods. In both the dipicolinate complexes, the dpc dianion acts as a tridentate ligand. In polymeric copper(II) complex, the 4-hymp and dpc ligands adopt a bridging position between the Cu(II) centers, forming the elongated octahedral geometry. The polymeric chains are linked to one another via O–H···O hydrogen bond interactions, forming the 3-D polymeric structure. The Ni(II) ion is bonded to dpc ligand through pyridine N atom together with one O atom of each carboxylate group, two aqua ligands and N pyridine atom of 4-hymp, forming the distorted octahedral geometry. The Ni(II) complexes are connected to one another via O–H···O hydrogen bonds, forming R 4 2 (18) motifs in 2-D pattern. The powder EPR spectra of copper(II) complex have indicated that the paramagnetic center is in rhombic symmetry with the Cu2+ ion having distorted octahedral geometry. IR and UV–Vis spectroscopes all agree with the observed crystal structure.

Kazak, Canan/0000-0003-2475-8775 WOS: 000268452100004 Nickel(II) dipicolinate complex containing 2-amino-4-methylpyrimidine (2A-4Mpy), [Ni(2A-4Mpy)(dpc) (H2O)(2)] center dot 2H(2)O was synthesized in solid state and its structural and spectroscopic properties were determined by XRD, IR, and UV-Vis techniques. The crystal data revealed that the Ni complex is in triclinic crystal systems with space group P-1 and Z = 2. The Ni(II) ion is bonded to dipicolinate ligand through pyridine N atom together with one O atom of each carboxylate group, 2 aqua ligands, and the N atom of 2-amino-4-methylpyrimidine, forming distorted octahedral geometry. IR and UV-Vis spectra of the complexes all agree with the observed crystal structure.

WOS: 000174630200014 Aspartame adduct of copper(II) chloride Cu(Asp)(2)Cl-2-2H(2)O (Asp= aspartame) is synthesized and characterized by elemental analysis, FT IR, UV/vis, ESR spectroscopies, TG, DTG, DTA measurements and molecular mechanics calculations. Aqueous solution of the green solid absorbs strongly at 774 and 367 nm. According to the Fr IR spectra, the aspartame moiety coordinates to the copper(II) ion via its carboxylate ends, whereas the ammonium terminal groups give rise to hydrogen bonding network with the water, the chloride ions or neighboring carboxylate groups. The results suggest tetragonally distorted octahedral environment of the copper ions. (C) 2002 Elsevier Science B.V. All rights reserved.

WOS: 000249759900135 The title complex, bis[2-(1H-imidazol-4-yl)ethanamine]disaccharinatonickel(II), [ Ni( C7H4NO3S) 2( C5H9N3) 2], has an octahedral coordination around the nickel(II) ion, and the Ni atom lies on a center of symmetry. The histamine ligands and sulfonyl group of the saccharinate ligands show disorder, and the two conformations (A and B, with almost equal occupancy) are inversion isomers. The molecular packing is stabilized by intra- and intermolecular hydrogen bonds between imidazole N atoms and sulfonyl O atoms. In the extended stucture, intermolecular N-H center dot center dot center dot O hydogen bonds constitute a chain structure parallel to the direction [110].

Naumov, Pance/0000-0003-2416-6569; Ibrahim, Abdul Razak/0000-0002-1982-9375 WOS: 000171453800009 The Cd atom in the title compound, [Cd(C7H4NO3S)(2) (C6H6N2O)(2) (H2O)(2)], lies on an inversion centre and is six-coordinate in an all-trans octahedral geometry. Hydrogen bonds involving a water molecule and the amido group of a nicotinamide ligand link adjacent molecules into layers.

WOS: 000478081200564 …

As a class of materials, metal phosphonates have been known for almost 30 years, but in recent years the research has expanded rapidly due to the important applications of metal bisphosphonate compounds in industrial processes such as ion-exchange, catalysis and sorption [1-3]. Recently, several metal complexes of clodronate, (dichloromethylene)-bisphosphonate, Cl2MBP, which is one of the best-documented bisphosphonates used effectively in medical applications, and its symmetrical dialkyl ester derivatives, have been prepared for studying the properties of solid materials [4]. The arrangement of metal complexes of bisphosphonates is dependent on the size of the organic group connected to the phosphonate groups, and also on the number of donor atoms of the ligand and on the degree of protonation of the phosphonate group [2]. In this study, a new, selective and simple method for the preparation of amide ester derivatives of Cl2MBP, has been developed. Four metal complexes of one of these synthesized ligands, P-piperidinium-P umethyl-(dichloromethylene)bis-phosphonate have been prepared in order to study the effect of the cyclic amine group on the complexing properties of the ligand and on the dimensionalities of its metal complexes. The compounds were crystallised by the gel method, and the structures of the complex crystals were characterized by single crystal X-ray diffraction methods, elemental analyses and thermal analyses. The methyl ester of piperidine derivative of Cl2MBP ligand forms the first wheel-like metal complex of bisphosphonate; the packing of the copper complex consist of channels occupied by aqua ligands and lattice water molecules. The complex, which has a unique hexameric structure, differs from rather common heptanuclear transition metal clusters such as Cu6Na, Co6Na, Fe6Na, Zn7, Mn7 and Cu7, where the seventh metal ion occupies the central position as a cation template. The other three compounds are polymers; Mg, Zn and Cd complexes consist of one-dimensional chains with different composition. In addition, in the case of the zinc complex, the coordinated Na cations hold the chains together forming a two-dimensional layered construction. Divalent metal cations are capable of forming different compounds with the methyl ester of piperidine derivative of clodronic acid. These kinds of structures provide new information about the ability of the amino derivatives of clodronic acid to form polymeric structures and microporous materials that can be utilized in chemical applications.